In the case of applying designs to steel plates by acid etching, pattern printing is performed on the steel plates using polymer resins, and then, portions of the steel plates without patterns printed thereon are dissolved in acid through acid etching to produce etching patterns. In addition, after the etching of steel plates, polymer pattern printed portions should be melted to expose the non-etched portions of the steel plates. Since products are produced through sequential operations of polymer pattern printing, drying, acid etching, washing, polymer pattern removal, and washing, the process may be complicated and operating costs may be high.
On the other hand, when a printed steel plate is manufactured by a method of applying a design to a steel plate using a solution, silica particles as a matting agent are added together with the solution to provide the feeling of etching with the solution. As a result, a feeling of etching may be realized by lowering the gloss of a solution. However, when an excessive amount of silica is added to a solution, the hardness of a paint film may be increased, processability may be poor, and resolution may be lowered. Further, in a printing process using inkjet printing, a phenomenon in which several micro-silica particles plug an ink jet nozzle may be problematic.
Color coated steel plates, for example, black coated steel plates, do not have pattern designs applied to the materials themselves. Thus, in order to achieve high quality in, and differentiation of, products, a technique of manufacturing a high quality color printed steel plate is required.